(n.) A low ridge.

bilge blain bleb blister blob boss bow bubble bulb bulge bulla bump bunch burl button cahot clump col comb condyle convex crest dowel ear esker flange flap gall gnarl handle hill hogback horseback hump hunch jog joggle kame knob knot knur knurl lip loop lump mole mountain nevus nub nubbin nubble papilloma peg rib ridge ring saddle saddleback shoulder spine stud style tab tubercle tubercule verruca vesicle wale wart welt